Critical issues for improving the treatment of alcoholism are what neurobiological changes are responsible for the transition from non-dependent alcohol use to alcoholism, and what persistent changes mediate relapse. The goals of the present proposal are to delineate brain biomarkers that indicate the neurobiological mechanisms responsible for alcohol escalation and to define brain biomarkers associated with relapse. To achieve these goals, we will test the following hypotheses: 1) Sufficient exposure to alcohol leads to changes in specific elements of the extended amygdala that produce elevations in the hedonic set point. In turn, this leads to progressive elevation in ethanol intake and a propensity to relapse during abstinence. 2) Self-administration of ethanol coupled with passive administration causes changes in protein expression levels and function more characteristic of the addictive process than passive administration alone. To test these hypotheses, we propose studies with the following Specific Aims: 1) To examine the effects of ethanol dependence on protein expression and modification with a focus on changes associated with ethanol reinforcement. 2) To determine long-lasting changes in protein expression and modification associated with vulnerability to relapse upon re-exposure to ethanol. Our proposed combination of cutting-edge behavioral, neuroanatomical, and proteomic approaches will permit the identification of important biomarkers that should enable the development of more specific and effective pharmacotherapy both to help block the process of alcohol addiction and prevent relapse in those suffering from alcoholism.